Field
The present disclosure generally relates to syringes, and, in particular, to syringes having a gravity-assisted valve.
Description of the Related Art
Medications and similarly dispensed substances are typically stored in a vial that is sealed with a vial cap having an access port for injecting fluid into or removing fluid from the vial. A closure of the vial usually include a pierceable rubber stopper formed of an elastomeric material such as butyl rubber or the like. The vial cap, typically formed of metal, is crimped over the pierceable rubber stopper and a flange of the vial to hold the stopper in place in the opening of the vial. The vial cap has an opening, or access port, through which the stopper and the vial opening may be accessed. A sharp cannula, such as a needle, or the piercing end of a vial adapter is typically inserted into the access port of a vial cap to make fluid connection with the contents of a vial.
Some medications for administration, such as many types of chemotherapy preparations, are packaged and shipped in a concentrated or dehydrated form, such as, but not limited to, a concentrated liquid or a dehydrated powder. Before these dehydrated or concentrated medicaments can be administered to patients, the medicaments must be reconstituted by adding a liquid rehydration or dilution component or constituent to the concentrated or dehydrated medicament. Gases from the reconstitution process, particularly for some chemotherapy preparations, can be toxic and require a closed or non-vented arrangement during processing and administration.